Electric heating unit



Feb. 9, 1932. pgc up 1,844,678

ELECTRIC HEATING UNIT Filed Dec. 17, 1928 Q GO 0 10 lnverafir- W 24 eorgef. Rbldup,

drawings in which'; V v Y Figlis an elevational view ofan'electrie heatmg Qpfthe invention. g I -yFvi 2is an 'enlargedlfragmentary'view or Patented Feb. -9, 1932 remasnn r cxnr, or onto, assiexon T rm: or i a c 1 --nwmomo,1ooaronanonor onrot,

" m v a 1 7.11 scan Ho. 32m 1 The nventioni relates generally to electric heating units," and more'particularly to heating units oif'the character'employed in-cook" stoves andthe' like. It is ageneral object of s'thi ven ion t p o heating unit a which shall economical" of manufacture,- quicklyjand easily assembled and such that its several parts may be readily accessible ,Hfor replacement or repair, without disturb i under tension. 7 I

- Anotherobject of the invention is to provide a; supportingmeans whichwill posi- V. .tivelysecure a heating element against bodily f displacement without restraining its move- :oment'axiallya Another object isto provide a retainer for.

a heating element, adapted for quick and easy 1 engagement or disengagement with a supporting base, and retained injengagement with its base through the normal tendency v of theheating element to bending.

Another object of the invention is to provide a retainer capable of effectively supporting sheeting element without the introduction 'ofsharp bends or turning points element, i

Other objects andadvantages will become apparent] from I the following description takenin connection'with the accompanying q i i ali e md a sn 1 a in'fengageinenttherewitli.

tween an ina pp t fin the b a isv-apers'peetive lview ,of a preferred a .v the, invention f'i of .vari

thereby eliminating stressed sections and consequently contributing to the lite o f the L rm d o a mer angularlydisposed t s awn 2! '1 tions Iha-ve shown in'the' and will herein describe in detail a preferred embodim'ent, but it is to be understood that I do not thereby intend to'limit the invention tothe specific form disclosed but intend to 'cover all modifications and alternative constructions falling withinthe and scope of the invention;

herein shown the invention embodied m a heating unit comprising a base 10 pref- 6o erably' of sheet metal and having an upturned peripheral flange 11 to afiord the necessary degree of rigidity to the base and likewise to provide a supportfor the circuit connections. The flange 11 is cut away at 55 oneside as at 12 to provide a seat for a terminal block of insulating material 13 in which are mounted the terminal connections 14. The terminal insulating block may be secured to the flange by means of bolts 15 10 and to the base plate proper by bolts 16. The heating unit may be supported within the stove in any desirable manner (not shown) so as to effect a rigid relation between oven and heater.

The invention contem lates. the use of a heatin element of usual orm such-as a coiled wire 0 i suitablecharacter. For the purpose of supporting the heating element upon the base 10 a novel retainer is provided. In the so present instance it is in the form of a block of insulating materialfsuch as porcelain and comprises a relatively thin pyramidal head I 17 having converging side edges 18 and a fiat base 19. The head is provided with a transs5 verse bore 20 whose diameter'i's such as to permit free movement of the heating element therethrough; i

Theretainer is adapted'for quick'and easy engagement and disengagement with the base 10 through the medium of a projection 21 integral with and depending from the. base i i i I of the supporting hes-(1117; "Said projection f ig 3 preferred manner fi ct nga interlockmg "en agement b comprisesa "cylindrical "portion -or stem 22 are diametrically radial'*'lu gs 23 spaced fromthe bottom of the base and The anchoring projection 21 with its diametrically disposed lugs 23 isadapted to be projected into an aperture 24 in the base 10 of the heating unit, which aperture is of a contour similar to that of the projection. It will be obvious that rotation of the support or retainer about its vertical axis, after engagement with an aperture in the base, will cause the lugs 23 to project beyond the edge of the aperture, thus locking the support againstbodily displacement with respect to the base. The base- 10 is provided with a series of apertures disposed so as to define a path along which a heating element may be normal path to effect engagement of the lugs with the apertures in the base. Upon being released the resiliency of the heating element 25 will rotate the support until the lugs are enabled to engage the underside of the base thus effectively preventing removal of a support without overcoming the normal tendencv of the heating element to resist bending.

It will be seen that by the construction provided it is possible to efiect quickly and easily engagement between the insulating support and the base. It is equally obvious that any particular section of the element may be removed to effect its repair without disturbance of the remaining supports upon the base, and consequently without removing the major portion of the element. Also, it

will be observed that the supporting retain-.

ers are held in operative relation to the base by the heating element, but without placing the latter under tension. and the bores 20 in the retainers are of such size as to permit free axial movement of the element and therefore prevent the introduction of stresses which would normally result from its tendency to expand and contract withalternate heating.

and cooling. j I

The heating unit is of course adapted for use in various ways and in a variety of positions. If used between two spaces to be heated, the apertures in the base are of such character asto provide openings through which 'directradiati'on may be secured from the coil to the opposite side of the base. I claim as my invention:

f 1. In anelectric heating unit, a base member. means on said base member defining a path along which a heating element may be supported, a plurality of insulating blocks ada ted to be mounted on said base and having ores formed therein, means spaced from said blocks and in rigid non-rotative relation thereto formed tocoact with said first means as the blocks are rotated to positions wherein said bores are substantially parallel to said path to interlockingly engage said blocks with said base, said blocks being freely movable between released and interlocked positions, a heating element threaded through the bores in said blocks and extending along said path, said heating element engaging the sides of said bores to hold said blocks against rotation and constituting the sole means act-- ing to retain said first means in interlocked relation with said second means.

2. In an electric heating unit, the combination of a base, a resilientcoiled resistance element extending along said base in spaced relation thereto, means supporting said element from said base' at points spaced longitudinally of said element, said base having an irregular opening therein adjacent to said element and between said points, said element normally extending across said opening in one direction, an insulating block having an aperture therein near one end thereof through which said element extends in snugand a lateral projection in a xed non-rotative position on the other end of said block adapt4 ed to register with and to be projected through. said opening by endwise movement of the block when the axis of said aperture is angularly displaced from said direction, said block and said projection being adaptedto be rotated to interlockingly engage said projection with said base when said axisis parallel to said direction, and said element acting yieldingly and as the sole means to maintain said projection in interlocked relation to said base. I

3. An electric heating unit comprising a base having a plurality of spaced irregular apertures therein, a plurality of insulating supports, one mounted in each of said apertures, each of said supports having a lateral projection in fixed relation thereon arranged to be interlocked with said base by rotation of said support, and each of said supports also having an opening therethrough spaced from said base, and a resilient heating element extending through said openings. so

as to be carried by said supports in spaced relation to said base and acting against the sides of said openings to hold said supports against rotation whereby said element constitutes the sole means acting to maintain the projections on said supports in interlocked relation with said base.

4. An electric heating unit comprising, in

combination, a base, a plurality of insulating ly fitting relation to the walls (if the aperture,

supports each having a bore formed therein, means in fixed non-rotative position on said base and cooperating means in fixed nonrotative position on each of said supports operable by rotation of said support about an axis perpendicular to said bore to interlock said support with said base, an electrical resistance element reeved through said bores, the relative diameters of the bores and said element being such as to permit axial and rotational movement of the element with respect to the axis of the bore, and said element engaging the sides of said bores to prevent rotation of said supports-whereby said element constitutes the sole means acting to maintain said two means in interlocked relation.

In testimony whereof, I have hereunto affixed my signature.

GEORGE E. PICKUP. 

